Lecture 1

Chemistry Definition

  • Chemistry is the science that deals with the materials of the universe and the changes these materials undergo.

Scientific Notation

  • Mass of DNA = 0.00000000000000050 grams = 5.0×10−165.0 \times 10^{-16}

  • Steps for writing Scientific/Exponential Notation:

    1. Move decimal point until coefficient between 1 and <10.

    2. Exponent (power of 10) equal to the number of places moved decimal

    3. (+) exponent if moved decimal to left (large numbers) (-) exponent if moved decimal to right (small numbers)

  • 321000=3.21×105321000 = 3.21 \times 10^{5}

  • 0.000790=7.90×10−40.000790 = 7.90 \times 10^{-4}

  • 9.1×10129.1 \times 10^{12}

    • coefficient exponent Scientific Notation!

  • 9,100,000,000,000=9.1×10129,100,000,000,000 = 9.1 \times 10^{12}